From EP-OS 0 663 348 A1 a device is known for emptying a film tube on the end of which is provided a ring whose edge area exceeds the inside diameter of a cartridge accommodating the film tube. The ring features a conical sealing surface which interacts with a sealing edge formed in the interior of a cap. When put into operation, the cap is pushed with its rear cylindrical end area onto a front end area of the cartridge, wherein the ring is centered and oriented axially and radially with a sealing surface in order to guarantee a proper engagement between sealing edge and sealing surface. The cap is penetrated by a delivery opening. This device is also utilized for the production of multicomponent mixtures.
In EP-OS 0 541 972 A1 a container for a multicomponent compound is disclosed. For each of the components a film tube is provided, each closed off with a clip at each side and each having a ring at one side, which is glued to the film tube. Each of the film tubes is inserted into one of two cylindrical chambers of a double cylinder. At one end face of the double cylinder, a headpiece is provided which is provided with a delivery opening for each of the housing chambers. The two delivery channels are constructed as crimped flow channels situated closely side by side and issuing into a nozzle. A bayonet mount or a screw mount is provided on the headpiece for fastening the nozzle to the headpiece. The nozzle is constructed as a static mixer.
In DE 296 06 463 U1 a device for emptying a tubular bag is disclosed, which features a headpiece in which two bags are arranged. The bags form a constructive unit, in which the bags are glued to the flange of the headpiece. Two separated flow channels lead to a mixing head which is placed onto a nipple.
In DE 43 35 970 A1 a headpiece with film bags as a constructive unit is likewise embodied, wherein a static mixer can be screwed onto the exit connector.
In order to avoid congestion of the headpieces, particularly the flow channels from becoming clogged in the case of curable multicomponent compounds, the halves of the headpiece are respectively marked by color, so that the user always places each component of a molding compound on the same side of the headpiece. In this way, each component is prevented from coming into contact with residues of the other component even inside the delivery openings, thus hardening and clogging the delivery openings and the static mixer.
As experience has shown, such constructions of devices are not only elaborate and expensive in production, but also unsatisfactory in use. As is known, a new mixer must be placed on the headpiece for each mixing process to generate a molding compound, for instance a hardenable impression-molding compound for dentistry purposes, since between two uses, unless they take place one immediately after the other, a hardening of the mixed components in the static mixer takes place.
So far, the static mixer has always had to remain connected to the headpiece in order to avoid a drying out and mixing of the components after use. The static mixers are exchanged only before the next usage. Before its next use, the static mixer, contaminated with blood, bacteria and so on, represents a permanent source of infection. Additionally, the dentist must touch the contaminated static mixer to exchange it, which creates a source of infection for the new patient.
When changing the static mixer, each time there is a movement transverse to the divided opening, whereby components in the opening area become mixed and react, that is, they solidify into a plug that clogs both the inlet to the static mixer and the flow channel of the headpiece. Additionally, the film bags must each be exchanged and one comes into contact with the individual substances via their exit openings. In order to avoid an unintended adhesion here as well, the headpieces must be cleaned which takes an extraordinary amount of time.
The pistons of the device are actuated in part by way of a hand lever. An application with a steady hand is thus not possible.
On the other hand, there is a need in everyday practice, particularly among dentists, for secure operating devices, which considerably ease the production of the aforementioned impression-molding compound for dentistry purposes in the respective volume desired. At the same time, adhesion of individual components to the fingers or to dental technicians'apparatus during exchange is extremely undesirable.
The invention is based on the problem of refining a device for mixing and delivering a multicomponent molding compound such that, while avoiding the aforementioned disadvantages, the operating readiness of the device can be guaranteed by simple means.
This problem is solved by the characteristics of the present invention.